An oxidation reaction is a basic reaction in the field of industrial organic chemistry, and there are a variety of known oxidation processes, in particular an oxidation process for a substrate using nitric acid. By way of illustration, adipic acid that is a raw material for the production of nylon 66 is prepared by a process of oxidizing cyclohexanol and no other, or a mixture of cyclohexanol and cyclohexanone (K/A oil) with nitric acid. An aromatic compound having a carboxyl group (e.g., benzoic acid) has been produced by a process that comprises oxidizing an aromatic compound having a methyl group (e.g., toluene) with nitric acid or dichromic acid.
Each of these processes, however, requires an expensive exhaust gas treatment plant for treatment of N.sub.2 O and NO.sub.x produced by the oxidation with nitric acid. Similarly, the case with dichromic acid requires treatment of a chromium component.
Polycyclic hydrocarbons each having a functional group in a bridgehead position are compounds applicable to many applications, and most of these compounds may be induced or derived from corresponding alcohols. In particular, polyols each substituted with hydroxyl groups on plural, i.e., two or more bridgehead positions can be advantageously employed for production of progressive materials (highly functional materials). However, it is difficult to introduce hydroxyl groups into the bridgehead positions of such chemically stable polycyclic hydrocarbons with effectiveness and high efficiency. By way of illustration, introduction of hydroxyl groups is conducted by bromination of a bridged cyclic hydrocarbon (e.g., adamantane or its derivative) with the use of excess bromine (e.g., 10 times by mole or more), and hydrolyzing the formed bromide with silver nitrate or silver sulfate in an excess amount greater than a stoichiometric amount (Chem. Ber., 92, 1629 (1959), 93, 226, 1161 (1960): J. Org. Chem., 26 2207 (1961)).
In this process, however, the reaction should be conducted over a long period at a temperature of about 100.degree. C. using a large quantity of bromine. Besides, the reaction consumes the expensive silver reagent in a large quantity. Moreover, successive bromination of two or more bridgehead positions would not be expected. In addition, since an adamantanetriol cannot be formed directly from adamantane, it has to be produced by isolation and hydrolysis of a successively highly brominated compound. Accordingly, the yield of the adamantanetriol is extremely low at about 10 to 30% [Tetrahedron Letters, 19 1841 (1967); Just. Liebigs Ann. Chem., 717 60 (1968)].
As a process for producing an adamantanediol, Japanese Patent Publication No. 16621/1967 (JP-B-42-16621) discloses that an adamantanediol is obtained by reacting adamantane with five times by mole or more of chromic acid in a concentrated acetic acid solution. However, in this technology, for a treatment of chromic component is needed, and in addition, although an adamantanediol is formed according to the process, oxidation of adamantane to a triol or higher polyol will not proceed, even when the reaction is carried out in severe conditions.
From the viewpoints of resource and environment, a preferable oxidation process is a catalytic oxidation in which molecular oxygen or air is directly used as an oxidizing agent. In page 762 of the "Lecture Draft II" (1994) of 67th Spring Annual Meeting of Chemical Society of Japan, it is reported that oxidation of an alcohol such as benzyl alcohol or benzhydrol with air using vanadomolybdophosphoriate and N-hydroxyphthalimide provides a ketone such as acetophenone or benzophenone in a high yield. Japanese Patent Application Laid-open No. 38909/1996 (JP-A-8-38909) discloses an oxidizing a substrate with oxygen by using the oxidation catalyst comprised an imide compound (e.g., N-hydroxyphthalimide) and a transition metal compound.
The catalytic systems show high activities in an oxidation of a substrate with oxygen. However, transformation rates or conversions or selectivities sometimes deteriorate depending on spieces of catalysts. When the catalytic activities are reduced and the amount of co-catalysts used is increased, it is difficult to continue the conduction of the oxidation reaction for a long time, because that the imide compound such as N-hydroxyphthalimide is deactivated in a short time.